Hi, I’ve had the Pro version for over 7 months and I just switched the payment option from monthly to yearly yesterday. Now there isn’t any subscription shown in the license menu.
Subscription changes should happen seamlessly, but there may be a delay at times until the App Store updates the ‘receipt’ stored on your device.
One thing you can try is to tap the ‘Restore’ button around on the purchase prompt. Doing this will force Infuse to check the App Store for a new/current subscription.